Liquid discharge head having a wiring substrate with surface wirings connected at both ends via through-wirings

Abstract

There is provided a liquid discharge head including a first wiring through which a drive signal is input to a wiring substrate, in which the wiring substrate has a substrate having a first surface and a second surface that opposes the first surface, a second wiring formed on the first surface, a third wiring formed on the second surface, a fourth wiring and a fifth wiring that pass through the substrate and electrically couples the second wiring with the third wiring, and an electrode provided on the second wiring and electrically couples the second wiring with the first wiring, and the electrode is positioned between a first coupling point at which the fourth wiring is electrically coupled to the second wiring and a second coupling point at which the fifth wiring is electrically coupled to the second wiring, in the second wiring.

What is claimed is: 
     
       1. A liquid discharge head comprising:
 a drive element driven by a drive signal supplied thereto; 
 an actuator substrate provided with the drive element; 
 drive circuit chip that controls a supply of the drive signal to the drive element; 
 a wiring substrate that propagates a source signal to the drive circuit chip and propagates the drive signal to the drive element, the wiring substrate having first and second surfaces facing outwardly opposite to each other; and 
 a first wiring through which the source signal is input to the wiring substrate via an input electrode on the first surface of the wiring substrate, 
 wherein the wiring substrate has:
 a first side and a second side that is longer than the first side; 
 a second wiring formed on the first surface and extending from one end to the other end of the wiring substrate along a first direction, the second side of the wiring substrate being along the first direction; 
 a third wiring formed on the second surface and extending from the one end to the other end of the wiring substrate along the first direction, the second wiring partially overlapping the third wiring in a plan view; 
 a first through wiring formed in the wiring substrate at the one end and electrically connecting between the second and third wirings; 
 a second through wiring formed in the wiring substrate at the other end and electrically connecting between the second and third wirings; 
 a first output electrode formed on the first surface at the other end; 
 a second output electrode formed on the second surface at the other end; and 
 a third through wiring formed in the wiring substrate at the other end and electrically connecting between the first and second output electrodes, 
 
 wherein the input electrode is formed on the second wiring at a position between the one end and the other end, 
 the source signal travels from the first wiring to the second wiring via the input electrode, from the second wiring to the third wiring via the first and second through wirings, and from the second wiring to the drive circuit chip, and 
 the drive signal travels from the drive circuit chip to the first output electrode to the second output electrode via the third through wiring, and from the second output electrode to the drive element. 
 
     
     
       2. The liquid discharge head according to  claim 1 , wherein
 the input electrode is provided between the fourth first through wiring and the second through wiring along the second side of the wiring substrate. 
 
     
     
       3. The liquid discharge head according to  claim 1 , wherein
 the drive circuit chip is provided on the wiring substrate, and 
 the input electrode is provided between the first through wiring and the drive circuit chip along the second side of the wiring substrate. 
 
     
     
       4. The liquid discharge head according to  claim 1 , wherein
 the second wiring includes a first buried wiring buried in the wiring substrate, 
 the third wiring includes a second buried wiring buried in the wiring substrate, and 
 a part of the first buried wiring overlaps with the input electrode in the plan view and a part of the second buried wiring overlaps with the input electrode in the plan view. 
 
     
     
       5. The liquid discharge head according to  claim 1 , wherein
 the wiring substrate further includes:
 a fourth through wiring formed in the wiring substrate and electrically connecting between the second and third wirings, and 
 
 the fourth through wiring is located between the input electrode and the second through wiring along the first direction. 
 
     
     
       6. A liquid discharge apparatus comprising:
 an external drive circuit configured to output a drive signal; and 
 a liquid discharge head, the liquid discharge head having:
 a drive element driven by the drive signal supplied from the external drive circuit; 
 an actuator substrate provided with the drive element; 
 a drive circuit chip that receives the drive signal from the external drive circuit to control a supply of the drive signal to the drive element; 
 a wiring substrate that propagates a source signal to the drive circuit chip and propagates the drive signal to the drive element, the wiring substrate having first and second surfaces facing outwardly opposite to each other; and 
 a first wiring through which the source signal is input to the wiring substrate via an input electrode on the first surface of the wiring substrate, 
 
 wherein the wiring substrate has:
 a first side and a second side that is longer than the first side; 
 a second wiring formed on the first surface and extending from one end to the other end of the wiring substrate along a first direction, the second side of the wiring substrate being along the first direction; 
 a third wiring formed on the second surface and extending from the one end to the other end of the wiring substrate along the first direction, the second wiring partially overlapping the third wiring in a plan view; 
 a first through wiring formed in the wiring substrate at the one end and electrically connecting between the second and third wirings; 
 a second through wiring formed in the wiring substrate at the other end and electrically connecting between the second and third wirings; 
 a first output electrode formed on the first surface at the other end; 
 a second output electrode formed on the second surface at the other end; and 
 a third through wiring formed in the wiring substrate at the other end and electrically connecting between the first and second output electrodes, 
 
 wherein the input electrode is formed on the second wiring at a position between the one end and the other end, 
 the source signal travels from the first wiring to the second wiring via the input electrode, from the second wiring to the third wiring via the first and second through wirings, and from the second wiring to the drive circuit chip, and 
 the drive signal travels from the drive circuit chip to the first output electrode to the second output electrode via the third through wiring, and from the second output electrode to the drive element. 
 
     
     
       7. A wiring substrate provided in a liquid discharge head, the wiring substrate having first and second surfaces facing outwardly opposite to each other, the liquid discharge head including a drive element driven by a drive signal supplied thereto, an actuator substrate provided with the drive element, a drive circuit chip that controls a supply of the drive signal to the drive element, and a first wiring through which a source signal is input to the wiring substrate via an input electrode on the first surface of the wiring substrate, the wiring substrate propagating the source signal to the drive circuit chip and propagating the drive signal to the drive element, the wiring substrate comprising:
 a first side and a second side that is longer than the first side; 
 a second wiring formed on the first surface and extending from one end to the other end of the wiring substrate along a first direction, the second side of the wiring substrate being along the first direction; 
 a third wiring formed on the second surface and extending from the one end to the other end of the wiring substrate along the first direction, the second wiring partially overlapping the third wiring in a plan view; 
 a first through wiring formed in the wiring substrate at the one end and electrically connecting between the second and third wirings; 
 a second through wiring formed in the wiring substrate at the other end and electrically connecting between the second and third wirings; 
 a first output electrode formed on the first surface at the other end; 
 a second output electrode formed on the second surface at the other end; and 
 a third through wiring formed in the wiring substrate at the other end and electrically connecting between the first and second output electrodes, 
 wherein the input electrode is formed on the second wiring at a position between the one end and the other end, 
 the source signal travels from the first wiring to the second wiring via the input electrode, from the second wiring to the third wiring via the first and second through wirings, and from the second wiring to the drive circuit chip, and 
 the drive signal travels from the drive circuit chip to the first output electrode to the second output electrode via the third through wiring, and from the second output electrode to the drive element.